Conventionally, pyridine and picolines are prepared from a reaction mixture comprising acetaldehyde, formaldehyde and ammonia using suitable catalysts, the aldehydes being the source of carbon. Since pyridine is in greater demand commercially than the picolines, it makes sound economic sense to try to enhance the pyridine-picoline product concentration in favor of pyridine. Furthermore, in view of the cost of formaldehyde, it would be quite advantageous to obviate its need or to substitute it with a less expensive reactant. Of course, still greater economy could be realized if any unused portions of the reactant substitute for formaldehyde could be recovered and recycled to subsequent reactant mixtures. This is not practical with present syntheses using formaldehyde, a handicap which represents considerable loss to the industry.
Pursuant to the present invention the disadvantages hereinbefore mentioned and other similar drawbacks which will become apparent are surmounted. These and a number of other advantages over the present art will be seen more clearly from the description which follows.